origins of life Flashcards
What is the “primordial soup” theory?
It suggests that early Earth had the right conditions for organic molecules to form in water, leading to the first life forms.
What experiment tested the idea that organic molecules could form in early Earth conditions?
The Miller-Urey Experiment simulated early Earth conditions and produced amino acids, supporting abiogenesis
What are the two main types of cells in life today?
Prokaryotic (bacteria, archaea) and Eukaryotic (plants, animals, fungi, protists).
What type of prokaryotes were likely the first photosynthetic organisms?
Photosynthetic prokaryotes, such as cyanobacteria, which helped create Earth’s oxygen-rich atmosphere
🃏 Q: What are two major groups of prokaryotes?
Bacteria and Archaea
What domain do humans and all multicellular life belong to?
Eukarya
What is a major difference between prokaryotic and eukaryotic cells?
Eukaryotic cells have a nucleus and membrane-bound organelles, while prokaryotic cells do not
What is abiogenesis?
The theory that life arose naturally from non-living matter.
What organic molecules are considered the building blocks of life?
Amino acids, nucleotides, lipids, and carbohydrates.
What does the endosymbiotic theory explain?
It explains how eukaryotic cells evolved from prokaryotic cells through symbiosis.
Which organelles are thought to have originated from symbiotic bacteria?
Mitochondria and chloroplasts
What evidence supports the endosymbiotic theory?
Mitochondria and chloroplasts have their own DNA, ribosomes, and double membranes, similar to bacteria.
What is a phylogenetic tree?
A diagram that shows evolutionary relationships between species.
What are homologous structures?
Similar structures in different species that suggest common ancestry (e.g., human arm and bat wing).
What is cladistics?
A method of classifying organisms based on shared evolutionary traits.
What are chemoautotrophs?
Organisms that get energy from inorganic molecules instead of sunlight.
What is a symbiotic relationship?
A close and long-term interaction between two different species, such as bacteria living inside eukaryotic cells.
